Medicinal leeches are leeches that are used for medicinal purposes. In the past, these bloodsucking creatures were a common treatment for a variety of ailments, including fevers or strange behavior. The use of leeches for medicinal purposes nearly stopped completely by the 20th century, but some medical professionals are once again using medicinal leeches.
A leech is a type of worm that feeds on the blood of animals, including reptiles and mammals. They can be found in most areas of the world, and they primarily live in fresh water. Some leeches, however, may also be found in salt water or even on land. Leeches generally have two suckers located on either end of their bodies, and their mouths are located in one of these suckers. Leeches will usually use their suckers to attach to animals before biting them.
Nearly any type of leeches can be used as medicinal leeches. Certain species of leeches, however, are more commonly used for this purpose. Some of the most common leech species used in medicine include Hirudo medicinalis, Hirudinaria manillensis, and Macrobdella decora.
Medicinal leeches have been used around the world for centuries. Ancient people often believed that physical and mental ailments were caused by evil spirits that lived in the blood. A practice known as bloodletting was very popular at this time, and this procedure basically entailed removing blood from a person's body, thereby removing the evil spirits with it. Since medicinal leeches suck blood, they were often used for this purpose.
Many historians agree, however, that the use of medicinal leeches was most popular around the 18th and 19th centuries. Many doctors during this time believed that too much blood in a person's body could cause any number of ailments, including fevers, rashes, headaches, and hemorrhoids. By allowing leeches to remove this blood, they believed they were curing a person's ailment.
It wasn't until the 20th century that the use of medicinal leeches began to decline. During this time, medical advances led most doctors to realize leeches could not actually treat most illnesses and ailments. In 2004, however, the United States Food and Drug Administration (FDA) approved the use of leeches in medicine, and the use of leeches in medicine is once again becoming popular.
It has been discovered that the saliva of leeches contains a strong anticoagulant. This substance prevents blood from clotting. For this reason, leeches can be used to help improve blood flow after certain types of surgery. Leeches are often used in surgeries that involve reattaching very small blood vessels that clot quickly. They can also be used to establish or improve blood circulation after reattaching severed digits.